If a two-mile taxi ride costs $3.90 then a mile will cost
= $3.90/2
= $1.95
Given that a five-mile ride in the same taxi costs $7.50 then the cost per mile
= $7.50/5
= $1.50
Comparing the rate per mile on both ocassion, it can be deduced that the higher the mileage the lower the cost per fare.
Let the charges of the taxi ride be fixed and variable with the fixed element as a and the variable element as b then
a + 2b = $3.90
a + 5b = $7.50
subtract 1 from 2
3b = $3.60
b = $1.20
a = $3.90 - 2($1.20)
a = $1.50
Hence for each ride, the taxi charges a fixed cost of $1.20 and an additional cost of $1.50 per mile